Apparatus for reproducing digital signals from a digital audio recording medium

Abstract

A digital signal reproducing apparatus in which the frequency of a basic clock signal generated from a clock generator having a fixed oscillation frequency is divided to produce a clock signal used for processing a digital signal, and, when the transmission speed of the digital signal is changed, the frequency division ratio is also changed to produce a clock signal synchronous with the digital signal transmitted at the changed transmission speed.

What is claimed is: 
     
       1. A digital audio signal reproducing apparatus for reproducing the digital audio signals recorded on a disk with a predetermined line speed and a predetermined sampling frequency, comprising: switching means for switching between a first reproduction transmission rate which is equal to the recorded transmission rate and a second reproduction transmission rate which is N times (N is an integer>1) the recorded transmission rate;   equalizing means, responsive to said switching means, for switching the frequency characteristic of the digital audio signals reproduced from said disk;   clock reproducing means for reproducing clock signals synchronized with said first and second reproduction transmission rates after shaping the output from said equalizing means;   signal processing means for detecting and correcting errors generated in the reproduced signals and for outputting said reproduced signals to a D/A converter;   control means for controlling rotation speed of said disk by the freuqency of synchronized signal detected in said reproduced signal;   oscillating means for oscillating at a fixed frequency; and   dividing means for dividing an output from said oscillating means by N such that an output from said dividing means can be used as a reference signal for said controlling means and said signal processing means.   
     
     
       2. A digital audio signal reproduction apparatus according to claim 1, wherein said clock reproducing means includes a small phase error at said first reproduction transmission rate and a large phase error at said second reproduction transmission rate. 
     
     
       3. A digital audio signal reproduction apparatus according to claim 2, wherein said clock reproducing means is digital data strobe circuit.